The present invention is generally directed to controls for ranges or other appliances for heating fluids and, in particular, to a method and apparatus for boil phase determination for use in connection with such appliances.
Boiling water or other fluids or foods (generically "liquids") is one of the most common uses of a range. It is typically desirable to closely monitor the boil phase of the liquid during such processes, i.e., to identify the pre-simmer, simmer onset, simmer and/or boil phases. In this regard, the pre-simmer phase is generally characterized by a calm liquid and the simmer onset phase is the initial, slow bubbling of the liquid characterized by the appearance of individual bubbles. During the simmer phase, bubbles appear in jets creating the effect commonly referred to as simmering. Finally, in the boil phase, the bubbling of the liquid is generalized, resulting in the familiar turbulence of a boiling liquid. These phases are easily identified by experts and experienced cooks.
The boil phase is monitored for a number of reasons. First, many cooking processes require that the liquid be attended to upon identification of a particular boil phase, e.g., reducing the heat after the liquid reaches a boil. In addition, the boil phase may be monitored to reduce heat upon boiling so as to prevent boil-over which can result in a burned-on mess or, in the case of gas ranges, extermination of the cooking flame. Moreover, a liquid not monitored upon boiling can boil dry resulting in burning of the food and a mess as well as presenting a potential hazard.
Generally, the boil phase is monitored visually. This is tedious, hence the common expression "watched water never boils." Such visual monitoring can interfere with the user's ability to prepare other foods or be otherwise fully productively disposed during heating of the liquid. Moreover, a busy or inexperienced cook may fail to accurately and in a timely manner identify a boil phase of interest. Accordingly, it would be beneficial to automatically monitor the boil phase of a liquid in order to provide greater convenience, cooking consistency and safety.